Enzyme Technology
Media for enzyme production
Detailed description of the development and use of fermenters
for the large-scale cultivation of microorganisms for enzyme production is
outside the scope of this volume but mention of media use is appropriate because
this has a bearing on the cost of the enzyme and because media components often
find their way into commercial enzyme preparations. Details of components used
in industrial scale fermentation broths for enzyme production are not readily
obtained. This is not unexpected as manufacturers have no wish to reveal
information that may be of technical or commercial value to their competitors.
Also some components of media may be changed from batch to batch as availability
and cost of, for instance, carbohydrate feedstocks change. Such changes reveal
themselves in often quite profound differences in appearance from batch to batch
of a single enzyme from a single producer. The effects of changing feedstocks
must be considered in relation to downstream processing. If such variability is
likely to significantly reduce the efficiency of the standard methodology, it
may be economical to use a more expensive defined medium of easily reproducible
composition.
Clearly defined media are usually out of the question for large
scale use on cost grounds but may be perfectly acceptable when enzymes are to be
produced for high value uses, such as analysis or medical therapy where very
pure preparations are essential. Less-defined complex media are composed of
ingredients selected on the basis of cost and availability as well as
composition. Waste materials and by-products from the food and agricultural
industries are often major ingredients. Thus molasses, corn steep liquor,
distillers solubles and wheat bran are important components of fermentation
media providing carbohydrate, minerals, nitrogen and some vitamins. Extra
carbohydrate is usually supplied as starch, sometimes refined but often simply
as ground cereal grains. Soybean meal and ammonium salts are frequently used
sources of additional nitrogen. Most of these materials will vary in quality and
composition from batch to batch causing changes in enzyme
productivity.
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This page was established in 2004 and last updated by Martin
Chaplin on
6 August, 2014
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